Sellafield

View over the facility to the Irish Sea

Sellafield is vast industrial complex on the coast of Cumberland devoted to nuclear power: specifically today to nuclear power fuel reprocessing and nuclear decommissioning. It is close to the village of Seascale, but dwarfs the village many times over.

The origin of the site is Royal Ordnance Factory Sellafield, established during the War. Later, a plant for manufacturing weapon's grade plutonium was built, known as the Windscale Piles, and soon afterwards the world's first commercialy operational nuclear power station, Calder Hall, was built here, opening in 1956. Other reactors and facilies were built around it over the following decades. The complex incorporates the Windscale site and four nuclear power generating reactors at Calder Hall, all of which are currently undergoing decommissioning and dismantling.

On site today are:

• Calder Hall (four reactors, being decommissioned)
• Windscale (being decommissioned)
• Magnox Reprocessing Plant
• First Generation Magnox Storage Pond
• Thermal Oxide Reprocessing Plant
• Highly Active Liquor Evaporation and Storage
• Waste Vitrification Plant
• Sellafield MOX Plan
• Enhanced Actinide Removal Plant
• Radioactive waste stores
• Fellside Power Station (gas-fired)
• Central Laboratory – National Nuclear Laboratory headquarters
• The Sellafield Centre

The site is owned by the Nuclear Decommissioning Authority. The operator is Sellafield Ltd.

Sellafield is served by Sellafield railway station.

Location

• Location map: 54°25’14"N, 3°29’51"W
• Streetmap: NY034036

The complex is on the coast of Cumberland, overlooking the Irish Sea, between the rivers Calder and Ehen. It was historically in the parish of St Bridget Beckermet and consisted of High Sellafield to the north and Low Sellafield: the latter township has been obliterated by the building of the complex.

Ownership and facilities

Sellafield was previously owned and operated by the United Kingdom Atomic Energy Authority and then, following the division of the authority in 1971, it was British Nuclear Fuels Ltd. Since 1 April 2005, it has been owned by the Nuclear Decommissioning Authority and is now operated under contract by Sellafield Ltd.

Activities at the Sellafield site primarily support decommissioning of historic plants, and reprocessing fuel from British and international nuclear reactors. Decommissioning projects include the Windscale Piles, Calder Hall, historic reprocessing facilities, waste stores, as well as other clean-up projects on the site. Reprocessing plants include the Thermal Oxide Reprocessing Plant|THORP nuclear fuel reprocessing plant, the Magnox nuclear reprocessing|nuclear fuel reprocessing plant, and the Waste Vitrification Plant. The site contains several nuclear waste stores, with the Low Level Waste Repository 6 km away at Drigg. The United Kingdom's National Nuclear Laboratory also has its Central Laboratory on the Sellafield site.

History

Sellafield was once a small, rural community in the parish of St Bridget Beckermet and consisting of two hamlets; High Sellafield and Low Sellafield. In the late nineteen the century the railway line down the coast of Cumberland reduced the isolation of this and neighbouring communities: Sellafield station was opended, and Sellafield Junction, for the branch line to [[Beckermet[[ and Egremont.

In 1942, during the Second World War, a Royal Ordnance Factory, known as ROF Sellafield, was built here, and Low Sellafield found itself incorporated in the factory complex. The nearby sister factory, ROF Drigg which produced trinitrotoluene] had been built in 1940, three miles to the south-east, at Drigg. The factories were built in these remote, coastal sites because of the hazardous nature of the process and to minimise the risk of enemy air attack. Both were classed as Explosive ROF specialising in high-explosive TNT (ROF Drigg) and propellant (ROF Sellafield). Production ceased at both factories immediately following the defeat of Japan.

After the War, the Sellafield site was briefly in the ownership of Courtaulds for development as a factory, but was reacquired by the Ministry of Supply to adapt the site for the production of materials for nuclear weapons, principally plutonium, and construction of the nuclear facilities commenced in September 1947. The site was renamed Windscale (after Windscale Nook, a bluff on the north bank of the River Calder) to avoid confusion with the Springfields uranium processing factory near Preston in Lancashire. The building of the nuclear plants at Windscale Works was a huge construction project, requiring a peak of 5000 workers. The two air-cooled and open-circuit, graphite-moderated Windscale reactors (the "Windscale Piles") constituted the first British weapons grade plutonium-239 production facility, built for the British nuclear weapons programme of the late 1940s and the 1950s. Windscale Pile No. 1 was operational in October 1950 (just over three years from the start of construction at Sellafield), and Pile No. 2 in June 1951. Windscale was also the site of the prototype British advanced gas-cooled reactor.

The site in 1956

With the creation of the United Kingdom Atomic Energy Authority in 1954, ownership of Windscale Works passed to the Authority. The first of four Magnox reactors became operational in 1956 at Calder Hall, adjacent to Windscale and across the River Calder, and the site became Windscale and Calder Works. Following the break-up of the UKAEA into a research division (UKAEA) and a production division, British Nuclear Fuels Ltd (BNFL) in 1971, the major part of the site was transferred to BNFL. In 1981 BNFL's Windscale and Calder Works was renamed Sellafield as part of a major reorganisation of the site – up to that time there was a General Manager of Windscale Works and a General Manager of Calder Works, but afterwards there was one Head of the entire BNFL Sellafield site – as well as to possibly attempt to disassociate the site from press reports about its safety. The remainder of the site remained in the hands of the UKAEA and was still called Windscale.

Since its inception as a nuclear facility, Sellafield has also been host to reprocessing operations, which separate the uranium, plutonium, and fission products from spent nuclear fuel. The uranium can then be used in the manufacture of new nuclear fuel, or in applications where its density is an asset. The plutonium can be used in the manufacture of mixed oxide fuel (MOX) for thermal reactors, or as fuel for fast breeder reactors, such as the Prototype Fast Reactor at Dounreay. These processes, including the associated cooling ponds, require considerable amounts of water and the licence to extract water from Wast Water, formerly held by BNFL, is now held by the Nuclear Decommissioning Authority.

On 19 April 2005, leaked radioactive waste was discovered from ThORP (Thermal Oxide reprocessing plant) through a crack into a sump chamber which may have started as early as August 2004, and was categorised as a level 3 event on the International Nuclear Event Scale, resulting in fines.

In February 2009, NuGeneration (NuGen), a consortium of GDF Suez, Iberdrola and Scottish and Southern Energy (SSE), announced plans to build a new nuclear power station of up to 3.6GW capacity at Sellafield. In October 2009, NuGen purchased an option to acquire land around Sellafield from the NDA for £70m.

On 18 October 2010, the government announced that Sellafield was one of the eight possible sites it considered suitable for future nuclear power stations. On 23 June 2011 the government confirmed the suitability of the site, and hoped an electricity generating company would choose to build a power station near Sellafield at Moorside by 2025.

Major plants

Windscale Piles

The Windscale Piles (centre and right)

Following the decision taken by the British government in January 1947 to develop nuclear weapons, Sellafield was chosen as the location of the plutonium production plant, consisting of the Windscale Piles and accompanying reprocessing plant to separate plutonium from the spent nuclear fuel. Unlike the early American nuclear reactors at Hanford, which consisted of a graphite core cooled by water, the Windscale Piles consisted of a graphite core cooled by air. Each pile contained almost 2,000 tons of graphite, and measured over 24 feet high by 50 feet in diameter. Fuel for the reactor consisted of rods of uranium metal, approximately 12 inches long by 1 inch in diameter, and clad in aluminium.

The initial fuel was loaded into the Windscale Piles in July 1950. By July 1952 the separation plant was being used to separate plutonium and uranium from spent fuel.

On 10 October 1957, the Windscale Piles were shut down following a fire in Pile 1 during a routine maintenance check, which destroyed the core and released an estimated 750 terabecquerels (20,000 curies) of radioactive material, including 22 TBq of Caesium-137 and 740 TBq of iodine-131 into the shafts. Thanks to innovative filters installed by Nobel laureate Sir John Cockcroft, 95% of the material was captured. As a precautionary measure, milk from surrounding farming areas was destroyed. Following the fire, Pile 1 was unserviceable, and Pile 2, although undamaged by the fire, was shut down as a precaution.

In the 1990s, the United Kingdom Atomic Energy Authority started to implement plans to decommission, disassemble and clean up both piles. In 2004 Pile 1 still contained about 15 tons of uranium fuel, and final completion of the decommissioning is not expected until at least 2037.

In 2014, radioactive sludge in the Pile Fuel Storage Pond (PFSP), built between 1948 and 1952, started to be repackaged in drums to reduce the "sludge hazard" and to allow the pond to be decommissioned. Decommissioning will require retrieval of sludge and solids, prior to dewatering and deconstruction, with retrievals planned for completion in 2016.

First Generation Reprocessing Plant

The first generation reprocessing plant was built to extract the plutonium from spent fuel to provide fissile material for the United Kingdom's atomic weapons programme, and for exchange with the United States through the US-UK Mutual Defence Agreement. It operated from 1951 until 1964, with an annual capacity of 300 tons of fuel, or 750 tons of low burn-up fuel. It was first used to reprocess fuel from the Windscale Piles, and was later repurposed to process fuel from UK Magnox reactors, however following the commissioning of the dedicated Magnox Reprocessing Plant, it was itself recycled to become a pre-handling plant to allow oxide fuel to be reprocessed in the Magnox plant, and was closed in 1973.

Magnox Reprocessing Plant

In 1964 the Magnox reprocessing plant came on stream to reprocess spent nuclear fuel from the Magnox reactors. The plant uses the "plutonium uranium extraction" Purex method for reprocessing spent fuel, with tributyl phosphate as an extraction agent. The Purex process produces uranium, plutonium and fission products as output streams. Over the 30 years from 1971 to 2001 the Magnox Reprocessing Plant has reprocessed over 35,000 tons of Magnox fuel, with 15,000 tons of fuel being regenerated.

First Generation Magnox Storage Pond (FGMSP)

The First Generation Magnox Storage Pond (FGMSP) was built to support reprocessing of fuel from UK Magnox power stations through the First Generation Reprocessing Plant, and was used for operations between 1960 until 1986. The pond is 66 feet wide, 492 feet long and 20 feet deep. A confinement wall is scheduled to be built in the future to help it withstand earthquakes.

As of 2014, the First Generation Magnox Storage Pond (FGMSP) remains as a priority decommissioning project. As well as nuclear waste, the pond holds about 1,200 cubic meters of radioactive sludge of unknown characteristics and 14,000 cubic meters of contaminated water. Decommissioning initially requires retrieval of the radioactive sludge into a newly built Sludge Packaging Plant 1, as well as fuel and skip retrieval. Completion of this will allow the dewatering and dismantling of the remaining structure. Future work will immobilise the sludge for long-term storage, and process solids through the Fuel Handling Plant for treatment and storage.

Calder Hall nuclear power station

Calder Hall - The world's first commercial nuclear power station

Calder Hall, first connected to the grid on 27 August 1956 and officially opened by Queen Elizabeth II on 17 October 1956, was the world's first power station to generate electricity on an industrial scale (four 60 MWe reactors) from nuclear energy; a 5 MWe experimental reactor at Obninsk in the Soviet Union had been connected to the public supply in 1954, and was the world's first nuclear power plant. The Calder Hall design was codenamed PIPPA (Pressurised Pile Producing Power and Plutonium) by the UKAEA to denote the plant's dual commercial and military role. Construction started in 1953. Calder Hall had four Magnox reactors capable of generating 60 MWe (net) of power each, reduced to 50 MWe in 1973. The reactors were supplied by UKAEA, the turbines by C. A. Parsons and Company, and the civil engineering contractor was Taylor Woodrow Construction. When the station closed on 31 March 2003, the first reactor had been in use for nearly 47 years.

In its early life Calder Hall primarily produced weapons-grade plutonium, with two fuel loads per year; electricity production was a secondary purpose. From 1964 it was mainly used on commercial fuel cycles; in April 1995 the Government announced that all production of plutonium for weapons purposes had ceased.

Cooling towers

Calder Hall had four cooling towers, built in 1950–56 to cool the water from the station. The towers were 290 feet in height and used the natural draught hyperboloid design. The towers stood for 50 years, creating a landmark visible from the village of Seascale. Conflict arose over renovating Calder Hall and preserving the towers, but costs effectively defeated all attempts to do so.

The four cooling towers were demolished by controlled implosions on Saturday 29 September 2007, by Controlled Demolition, Inc. A period of 12 weeks was required to remove asbestos in the towers' rubble.

Windscale Advanced Gas Cooled Reactor (WAGR)

The Windscale Advanced Gas Cooled Reactor (WAGR) was a prototype for the UK's second generation of reactors, the advanced gas-cooled reactor or AGR, which followed on from the Magnox stations. The WAGR golfball is, along with the pile chimneys, one of the iconic buildings on the Windscale site (Windscale being an independent site within the Sellafield complex). Construction was carried out by Mitchell Construction and completed in 1962. This reactor was shut down in 1981, and is now part of a pilot project to demonstrate techniques for safely decommissioning a nuclear reactor.

Thermal Oxide Reprocessing Plant

Between 1977 and 1978 an inquiry was held into an application by BNFL for outline planning permission to build a new plant to reprocess irradiated oxide nuclear fuel from both UK and foreign reactors. The inquiry was used to answer three questions:

"1. Should oxide fuel from United Kingdom reactors be reprocessed in this country at all; whether at Windscale or elsewhere?
2. If yes, should such reprocessing be carried on at Windscale?
3. If yes, should the reprocessing plant be about double the estimated site required to handle United Kingdom oxide fuels and be used as to the spare capacity, for reprocessing foreign fuels?"

The result of the inquiry was that the new plant, the Thermal Oxide Reprocessing Plant (Thorp) was given the go ahead in 1978, although it did not go into operation until 1994.

On 19 April 2005 83,000 litres of radioactive waste was discovered to have leaked in the Thorp reprocessing plant from a cracked pipe into a huge stainless steel-lined concrete sump chamber built to contain leaks. No radiation was released to the environment, and no one was injured by the incident, but because of the large escape of radioactivity to the secondary containment the incident was given an International Nuclear Event Scale level 3 categorisation. Sellafield Limited was fined £500,000 for breaching health and safety law. In January 2007 Sellafield was given consent to restart Thorp.

Highly Active Liquor Evaporation and Storage

Highly Active Liquor Evaporation and Storage (HALES) is a department at Sellafield. It conditions nuclear waste streams from the Magnox and Thorp reprocessing plants, prior to transfer to the Waste Vitrification Plant.

Waste Vitrification Plant

In 1991 the Waste Vitrification Plant (WVP), which seals high-level radioactive waste in glass, was opened. In this plant, liquid wastes are mixed with glass and melted in a furnace, which when cooled forms a solid block of glass.

The plant has three process lines and is based on the French AVM procedure. Principal item is an inductively heated melting furnace, in which the calcined waste is merged with glass frit (glass beads of 1 to 2 mm in diameter). The melt is placed into waste containers, which are welded shut, their outsides decontaminated and then brought into air-cooled storage facilities. This storage consists of 800 vertical storage tubes, each capable of storing ten containers. The total storage capacity is 8000 containers, and 5000 containers have been stored to 2010. Vitrification is intended to ensure safe storage of waste in the United Kingdom for the middle to long term.

Sellafield MOX Plant

Construction of the Sellafield MOX Plant (SMP) was completed in 1997, though justification for the operation of the plant was not achieved until October 2001. Mixed oxide, or MOX fuel, is a blend of plutonium and natural uranium or depleted uranium which behaves similarly (though not identically) to the enriched uranium feed for which most nuclear reactors were designed. MOX fuel is an alternative to low enriched uranium (LEU) fuel used in the light water reactors which predominate in nuclear power generation. MOX also provides a means of using excess weapons-grade plutonium (from military sources) to produce electricity.

Designed with a plant capacity of 120 tons/year, it achieved a total output of only 5 tons during its first five years of operation. In 2008 orders for the plant had to be fulfilled at COGEMA in France, and the plant was reported in the media as "failed" with a total construction and operating cost of £1.2 billion.

On 12 May 2010 an agreement was reached with existing Japanese customers on future MOX supplies. In July 2010 Areva was contracted to design and supply a new rod line to improve reliability and production rate.

On 3 August 2011 the Nuclear Decommissioning Authority announced that the MOX Plant would close, due to the loss of Japanese orders following the Fukushima Daiichi nuclear disaster. Japanese orders for MOX recommenced on 17 April 2013, being supplied by the Sellafield MOX plant's main competitor, the French MOX fuel vendor COGEMA owned by Areva.

Enhanced Actinide Removal Plant

Since its early days, Sellafield has treated waste and allowed cleaned material to discharge into the sea, using a flocculation process to remove radioactive elements from liquid effluent before discharge. Metals dissolved in acidic effluents produced a metal hydroxide flocculant precipitate following the addition of ammonium hydroxide. The suspension was then transferred to settling tanks where the precipitate would settle out, and the remaining clarified liquid, or supernate, would be discharged to the Irish Sea. In 1994 the Enhanced Actinide Removal Plant (EARP) was opened. In EARP the effectiveness of the process is enhanced by the addition of reagents to remove the remaining soluble radioactive species. EARP was enhanced in 2004 to further reduce the quantities of Technetium-99 released to the environment.

Radioactive waste stores

Sellafield has several radioactive waste stores, mostly on an interim basis while a national waste repository plan is developed and implemented. The stores include:

• Legacy Ponds and Silos – Storage of historic waste
• Sludge packaging plant – Treatment and interim storage of sludges from legacy ponds
• Sellafield product and residue store – Site store for plutonium and plutonium residues – The plutonium stockpile estimated in November 2013 at 100 tons.
• Engineered drum stores – Site stores for plutonium contaminated material
• Encapsulated product stores – Site stores for grouted wastes
• Vitrified product store – Vitrified high level waste

The UK's main Low Level Waste Repository for nuclear waste is four miles south east of Sellafield at Drigg. A paper published in 1989 said that 70% of the waste received at Drigg originated from Sellafield.

Fellside Power Station

Fellside Power Station is a 168 MWe Cogeneration ("CHP") gas-fired power station near the Sellafield site, which it supplies with steam and heat. It is run as Fellside Heat and Power Ltd, is wholly owned by Sellafield Ltd and is operated & managed by PX Ltd. It was built in 1993, being originally equally owned by BNFL and Scottish Hydro Electric (which became Scottish and Southern Energy in December 1998). The station uses three General Electric Frame 6001B gas turbines, with power entering the National Grid via a 132kV transformer. The turbines in Fellside Power Station are natural gas fired and are also able to run on distillate (diesel) fuel. BNFL bought SSE's 50% share in January 2002.

Sellafield and the local community

Sellafield directly employs around 10,000 people and is one of the two largest non-governmental employers in West Cumbria (along with BAE Systems at Barrow-in-Furness), with approximately 90% of the employees coming from West Cumbria. Because of the increase in local unemployment following any run down of Sellafield operations, the Nuclear Decommissioning Authority (and ther Government) is concerned that this needs to be managed.

Central Laboratory – National Nuclear Laboratory headquarters

The Central Laboratory at Sellafield is the headquarters of the National Nuclear Laboratory and is the flagship nuclear Research and Development facility in the United Kingdom. It supports newly built reactors, operation of reactors, operations of fuel processing plants and decommissioning and clean-up. The NNL's Central Laboratory is available to run a wide range of radioactive and non-radioactive experimental programmes. In addition, it offers a wide range of analytical services, building on its location on the Sellafield site and considerable expertise of its resident technologists. Customers range from Government and the NDA to site licence companies, utilities, nuclear specialists and universities. The facility has been designed with flexibility and collaboration firmly at its heart. Smaller experiments can be easily set, taking advantage of the modular nature of the laboratories. Larger experiments and rigs can be assembled off site, installed and pre-tested in non-radioactive areas prior to active testing.

Sellafield Centre – Business and Information Centre

Sellafield Visitors' Centre

At its peak, the Sellafield Visitors' Centre attracted an average of 1,000 people a day. In recent years, its popularity deteriorated, prompting the change from tourist attraction to conference facility. It is now the Business and Information Centre and is open Mon – Fri only. The centre is used for business events such as supplier forums and 'Meet the Buyer' events. The Visitors Centre is completely closed, and there are no areas for the public to visit.

Decommissioning

Sellafield's biggest decommissioning challenges relate to the leftovers of the early nuclear research and nuclear weapons programmes. Sellafield houses "the most hazardous industrial building in western Europe" (building B30) and the second-most (building B38), which hold a variety of leftovers from the first Magnox plants in ageing ponds. Some of the problems with B38 date back to the 1972 miners' strike: the reactors were pushed so hard that waste processing could not keep up, and "cladding and fuel were simply thrown into B38's cooling ponds and left to disintegrate." Some of the problems date back to the original nuclear weapons programme at Sellafield, when Piles 1 and 2 were constructed at breakneck speed, and safe disposal was not a priority. Building B41 still houses the aluminium cladding for the uranium fuel rods of Piles 1 and 2, and is modelled on a grain silo, with waste tipped in at the top and argon gas added to prevent fires.

Outside links

("Wikimedia Commons" has material about Sellafield)

Official information

• Nuclear Decommissioning Authority
• Sellafield Ltd
• British Nuclear Fuels Ltd
• National Nuclear Laboratory

1957 fire

• An article on the Windscale fire, by the Lake District Tourist Board
• Nuclear Tourist
• BBC retrospective on the accident report

2005 leak

• Board of Inquiry Report

Other

• "Britain's Pioneer Atomic Power Plants." Popular Mechanics, June 1954, pp. 74–75, cutaway drawing of facilities.
• Sellafield awaits nuclear power's rebirth, by Jorn Madslien, BBC News
• The sale of Britain's nuclear giant, by Jorn Madslien, BBC News
• "Blast from the past" Guardian article
• Annotated references on Sellafield from the Alsos Digital Library for Nuclear Issues
• Calder Hall, Nuclear Engineering International wall chart, October 1956

References

• Ritchie, Berry (1997). The Good Builder: The John Laing Story. James & James. 
• Sellafield Stories at local authority oral history project